Aluminum or aluminum carbide alternative catalyst for polycrystalline diamond compact formation

ABSTRACT

A superabrasive compact and a method of making the superabrasive compact are disclosed. A superabrasive compact may comprise a superabrasive volume comprising about 60 to about 99.5 weight % superabrasive particles, about 0.5 to 40 weight % catalysts. The catalyst comprises a non-transitional metal atom.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application claims priority of U.S. provisional application No. 61/910,349, filed on Nov. 30, 2013, titled “aluminum or aluminum carbide alternative catalyst for polycrystalline diamond compact formation.”

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY

The present invention relates generally to superabrasive materials and a method of making superabrasive materials, and more particularly, to polycrystalline diamond compacts (PDC) made from surface functionalized diamond particle.

SUMMARY

In one embodiment, a superabrasive compact may comprise a substrate and a superabrasive volume attached to the substrate, wherein the superabrasive volume has a plurality of polycrystalline superabrasive particles and a first catalyst, wherein the first catalyst comprises a non-transitional metal atom.

In another embodiment, a method of making a superabrasive compact may comprise steps of mixing a metal with a plurality of diamond particles; subjecting the metal and the plurality of diamond particles to conditions of elevated temperature and pressure suitable for producing the polycrystalline diamond compact; and converting the metal to a metal carbide under the elevated temperature and pressure.

In yet another embodiment, a superabrasive compact may comprise a superabrasive volume comprising about 60 to about 99.5 weight % superabrasive particles, about 0.5 to 40 weight % catalysts, wherein the catalyst comprises a non-transitional metal atom.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description of the embodiments, will be better understood when read in conjunction with the appended drawings. It should be understood that the embodiments depicted are not limited to the precise arrangements and instrumentalities shown.

FIG. 1 is schematic perspective view of a cylindrical shape polycrystalline compact produced in a high pressure high temperature (HPHT) process according to an embodiment; and

FIG. 2 is a flow chart illustrating a method of manufacturing polycrystalline compact according to an embodiment.

DETAILED DESCRIPTION

Before the description of the embodiment, terminology, methodology, systems, and materials are described; it is to be understood that this disclosure is not limited to the particular terminologies, methodologies, systems, and materials described, as these may vary. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions of embodiments only, and is not intended to limit the scope of embodiments. For example, as used herein, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. In addition, the word “comprising” as used herein is intended to mean “including but not limited to.” Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art.

Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as size, weight, reaction conditions and so forth used in the specification and claims are to the understood as being modified in all instances by the term “about”. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

As used herein, the term “about” means plus or minus 10% of the numerical value of the number with which it is being used. Therefore, about 50% means in the range of 45%-55%.

As used herein, the term “superabrasive particles” may refer to ultra-hard particles or superabrasive particles having a Knoop hardness of 3500 KHN or greater. The superabrasive particles may include diamond and cubic boron nitride, for example. The term “abrasive”, as used herein, refers to any material used to wear away softer material.

The term “particle” or “particles”, as used herein, refers to a discrete body or bodies. A particle is also considered a crystal or a grain.

The term “superabrasive compact”, as used herein, refers to a sintered product made using super abrasive particles, such as diamond feed or cubic boron nitride particles. The compact may include a support, such as a tungsten carbide support, or may not include a support. The “superabrasive compact” is a broad term, which may include cutting element, cutters, or polycrystalline cubic boron nitride insert.

The term “cutting element” , as used herein, means and includes any element of an earth-boring tool that is used to cut or otherwise disintegrate formation material when the earth-boring tool is used to form or enlarge a bore in the formation.

The term “earth-boring tool”, as used herein, means and includes any tool used to remove formation material and form a bore (e.g., a wellbore) through the formation by way of the removal of the formation material. Earth-boring tools include, for example, rotary drill bits (e.g., fixed-compact or “drag” bits and roller cone or “rock” bits), hybrid bits including both fixed compacts and roller elements, coring bits, percussion bits, bi-center bits, reamers (including expandable reamers and fixed-wing reamers), and other so-called “hole-opening” tools.

The term “feed” or “diamond feed”, as used herein, refers to any type of diamond particles, or diamond powder, used as a starting material in further synthesis of PDC compacts.

The term “polycrystalline diamond”, as used herein, refers to a plurality of randomly oriented monocrystalline diamond particles, which may represent a body or a particle consisting of a large number of smaller monocrystalline diamond particles of any sizes. Polycrystalline diamond particles usually do not have cleavage planes.

The term “superabrasive”, as used herein, refers to an abrasive possessing superior hardness and abrasion resistance. Diamond and cubic boron nitride are examples of superabrasives and have Knoop indentation hardness values of over 3500.

The terms “diamond particle” or “particles” or “diamond powder”, which is a plurality of a large number of single crystal or polycrystalline diamond particles, are used synonymously in the instant application and have the same meaning as “particle” defined above.

Polycrystalline diamond compact (or “PDC”, as used hereinafter) may represent a volume of crystalline diamond grains with embedded foreign material filling the inter-grain space. In one particular case, a compact comprises crystalline diamond grains, bound to each other by strong diamond-to-diamond bonds and forming a rigid polycrystalline diamond body, and the inter-grain regions, disposed between the bounded grains and filled in one part with a catalyst material (e.g. cobalt or its alloys), which was used to promote diamond bonding during fabrication, and in other part filled with other materials which may remain after the sintering of diamond compact. Suitable metal solvent catalysts may include the iron group transitional metal in Group VIII of the Periodic table. In another particular case, a polycrystalline diamond composite compact comprises a plurality of crystalline diamond grains, which are not bound to each other, but instead are bound together by foreign bonding materials such as borides, nitrides, carbides, and others, e.g. by silicon carbide bonding material.

Polycrystalline diamond compacts (or PDC compacts) may be fabricated in different ways and the examples discussed herein do not limit a variety of different types of diamond composites and PDC compacts which may be produced according to an embodiment. In one particular example, polycrystalline compacts are formed by placing a mixture of diamond powder with a suitable solvent catalyst material (e.g. cobalt powder) on the top of WC—Co substrate, the assembly is then subjected to conditions of HPHT process, where the solvent catalyst promotes desired inter-crystalline diamond-to-diamond bonding resulted in the formation of a rigid polycrystalline diamond body and, also, provides a binding between polycrystalline diamond body and WC—Co substrate.

In another particular example, a polycrystalline diamond compact is formed by placing diamond powder without a catalyst material on the top of substrate containing a catalyst material (e.g. WC—Co substrate). In this example, necessary cobalt catalyst material is supplied from the substrate and melted cobalt is swept through the diamond powder during the HPHT process. In still another example, a hard polycrystalline diamond composite compact is fabricated by forming a mixture of diamond powder with silicon powder and the mixture is subjected to HPHT process, thus forming a dense polycrystalline compact where diamond particles are bound together by newly formed aluminum carbide material.

The presence of catalyst materials inside of the polycrystalline diamond body promotes the degradation of the cutting edge of the compact during the cutting process, especially if the edge temperature reaches a high enough critical value. It is theorized that the cobalt driven degradation may be caused by the large difference in thermal expansion between diamond and catalyst (e.g. cobalt metal), and also by the catalytic effect of cobalt on diamond graphitization. Removal of catalyst from the polycrystalline diamond body of PDC compact, for example, by chemical leaching in acids, leaves an interconnected network of pores and a residual catalyst (up to about 10 vol %) trapped inside the polycrystalline diamond body. It has been demonstrated that depletion of cobalt from the polycrystalline diamond body of the PDC compact significantly improves a compact's abrasion resistance. Thus, it is theorized that a thicker cobalt depleted layer near the cutting edge, such as more than about 100 μm provides better abrasion resistance of the PDC compact than a thinner cobalt depleted layer, such as less than about 100 μm.

A superabrasive compact 10 in accordance with a current embodiment is shown in FIG. 1. Superabrasive compact 10 may be inserted into a downhole of a suitable tool, such as a drill bit, for example. One example of the superabrasive compact 10 may include a superabrasive volume 12 having a top surface 21. The superabrasive compact may comprise a plurality of polycrystalline superabrasive particles and a first catalyst, such as aluminum carbide or aluminum. The first catalyst may comprise a non-transitional metal atom, such as aluminum atom. The superabrasive particle may comprise a diamond particle. The superabrasive volume may comprise about 60 to 99.5 weight % superabrasive particles and about 0.5 to about 40 weight % catalysts, such as aluminum or aluminum carbide. The aluminum carbide may be an intermediate forming from aluminum and diamond at an elevated temperature and pressure, such as about 1400° C. to about 2500° C. and about 10 to about 80 Kbar, respectively or about 2000° C. to about 2500° C. and about 10 to about 80 Kbar, respectively. At the elevated temperature and pressure, aluminum may be substantially converted to aluminum carbide in such that the superabrasive volume may be substantially free of a metal.

In one embodiment, the superabrasive compact 10 may be a standalone compact without a substrate. In another embodiment, the superabrasive compact 10 may include a substrate 20 attached to the superabrasive volume 12 formed by polycrystalline superabrasive particles. The substrate 20 may be metal carbide, attached to the superabrasive volume 12 via an interface 22 separating the superabrasive volume 12 and the metal carbide. Substrate 20 may be made from cemented cobalt tungsten carbide, or tungsten carbide, while the superabrasive volume 12 may be formed from a polycrystalline ultra-hard material, such as polycrystalline diamond, polycrystalline cubic boron nitride (“PCBN”), tungsten carbide mixed with diamond crystals (impregnated segments), or diamond crystals bonded by a foreign material. The first catalyst, such as aluminum or aluminum carbide, in the superabrasive volume may have a lower coefficient of thermal expansion (CTE) than a second catalyst from the substrate 20. The second catalyst may be an iron group transitional metal, such as cobalt.

The superabrasive compact 10 may be fabricated according to processes known to persons having ordinary skill in the art. Methods for making diamond compacts and composite compacts are more fully described in U.S. Pat. Nos. 3,141,746; 3,745,623; 3,609,818; 3,850,591; 4,394,170; 4,403,015; 4,794,326; and 4,954,139.

The compact 10 may be referred to as a polycrystalline diamond compact (“PDC”) when polycrystalline diamond is used to form the polycrystalline volume 12. PDC compacts are known for their toughness and durability, which allow them to be an effective cutting insert in demanding applications. Although one type of superabrasive compact 10 has been described, other types of superabrasive compacts 10 may be utilized. For example, in one embodiment, superabrasive compact 10 may have a chamfer (not shown) around an outer peripheral of the top surface 21. The chamfer may have a vertical height of about 0.5 mm and an angle of about 45° degrees, for example, which may provide a particularly strong and fracture resistant tool component. In another embodiment, the superabrasive compact 10 may be a subject of procedure depleting catalyst metal (e.g. cobalt) near the cutting surface of the compact, for example chemical leaching of cobalt in acidic solutions.

As shown in FIG. 2, a method 20 of making superabrasive compact may comprise the steps of mixing a metal, such as a non-transitional metal, with a plurality of diamond particles in a step 22; subjecting the metal and the plurality of diamond particles to conditions of elevated temperature and pressure suitable for producing the polycrystalline diamond compact in a step 24; converting the metal, such as aluminum, to a metal carbide, such as aluminum carbide, under the elevated temperature and pressure in a step 26.

The method 20 of making a superabrasive compact may further comprise a step of providing a substrate, cemented tungsten carbide, attached to a volume made of the metal and the plurality of diamond particles before subjecting the metal and the plurality of diamond particles to conditions of elevated temperature and pressure. The non-transitional metal may comprise metal, such as aluminum. In one embodiment, the elevated temperature and pressure may be about 1400° C. to about 2500° C. and about 10 to about 80 Kbar, respectively. In another embodiment, the elevated temperature is about 2000° C. to about 2500° C. The aluminum or aluminum carbide may be melting and reacting with diamond to form aluminum carbide (Al₄C₃) at elevated temperature and pressure. Aluminum carbide or aluminum may be used as a catalyst for diamonds to form diamond to diamond bonds, such as sp³ bonding.

One or more steps may be inserted in between or substituted for each of the foregoing steps 22-26 without departing from the scope of this disclosure.

While reference has been made to specific embodiments, it is apparent that other embodiments and variations can be devised by others skilled in the art without departing from their spirit and scope. The appended claims are intended to be construed to include all such embodiments and equivalent variations. 

1. A superabrasive compact, comprising: a substrate; and a superabrasive volume attached to the substrate, wherein the superabrasive volume has a plurality of polycrystalline superabrasive particles and a first catalyst, wherein the first catalyst comprises a non-transitional metal atom.
 2. The superabrasive compact of the claim 1, wherein the superabrasive particle comprises diamond particle.
 3. The superabrasive compact of the claim 1, wherein the superabrasive volume comprises about 60 to about 99.5 weight % diamond, about 0.5 to 40 weight % aluminum carbide or aluminum.
 4. The superabrasive compact of the claim 1, wherein the non-transitional metal atom comprises aluminum.
 5. The superabrasive compact of the claim 1, wherein the substrate comprises a second catalyst for forming the superabrasive particle to particle bonding.
 6. The superabrasive compact of the claim 1, wherein the second catalyst is an iron group transitional metal.
 7. A method of making a superabrasive compact, comprising: mixing a metal with a plurality of diamond particles; subjecting the metal and the plurality of diamond particles to conditions of elevated temperature and pressure suitable for producing the polycrystalline diamond compact; and converting the metal to a metal carbide under the elevated temperature and pressure.
 8. The method of the claim 7, further comprising providing a substrate attached to a volume made of the metal and the plurality of diamond particles before subjecting the metal and the plurality of diamond particles to conditions of elevated temperature and pressure.
 9. The method of claim 8, wherein the substrate is cemented tungsten carbide.
 10. The method of the claim 7, wherein the metal comprises a non-transitional metal.
 11. The method of the claim 7, wherein the metal and the metal carbide are aluminum to aluminum carbide, respectively.
 12. The method of the claim 7, wherein the elevated temperature and pressure are about 1400° C. to about 2500° C. and about 10 to about 80 Kbar, respectively.
 13. The method of the claim 7, wherein the elevated temperature is about 2000° C. to about 2500° C.
 14. The method of the claim 11, wherein aluminum carbide or aluminum is used as a catalyst for diamonds to form diamond to diamond bonds.
 15. A superabrasive compact, comprising: a superabrasive volume comprising about 60 to about 99.5 weight % superabrasive particles, about 0.5 to about 40 weight % catalysts, wherein the catalyst comprises a non-transitional metal atom.
 16. The superabrasive compact of the claim 15, wherein the superabrasive particles are selected from a group of cubic boron nitride, diamond, and diamond composite materials.
 17. The superabrasive compact of the claim 15, wherein the non-transitional metal atom is aluminum.
 18. The superabrasive compact of claim 15, wherein the catalyst is aluminum or aluminum carbide.
 19. The superabrasive compact of claim 18, wherein the aluminum carbide is an intermediate forming from aluminum and diamond at elevated temperature and pressure.
 20. The superabrasive compact of the claim 15, further comprises a substrate attached to a superabrasive volume formed by the polycrystalline superabrasive particles.
 21. The superabrasive compact of the claim 20, wherein the substrate is a cemented tungsten carbide.
 22. The superabrasive compact of the claim 15, wherein the superabrasive volume is substantially free of a metal. 